28406340 has 36 divisors (see below), whose sum is σ = 86166444. Its totient is φ = 7574976.

The previous prime is 28406327. The next prime is 28406347. The reversal of 28406340 is 4360482.

28406340 is a `hidden beast` number, since 28 + 4 + 0 + 634 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 19079424 + 9326916 = 4368^2 + 3054^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (28406347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 78727 + ... + 79086.

Almost surely, 2^28406340 is an apocalyptic number.

28406340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28406340 is an abundant number, since it is smaller than the sum of its proper divisors (57760104).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28406340 is a wasteful number, since it uses less digits than its factorization.

28406340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 157828 (or 157823 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 28406340 is about 5329.7598444958. The cubic root of 28406340 is about 305.1207619972.

It can be divided in two parts, 2840 and 6340, that added together give a triangular number (9180 = T₁₃₅).

The spelling of 28406340 in words is "twenty-eight million, four hundred six thousand, three hundred forty".